Analysis of the Temporal and Spatial Characteristics of the Pacific Decadal Oscillation in Global Warming Scenarios

In this paper, based on historical and global warming scenarios and observed sea temperature data in the Coupled Model Intercomparison Project Phase 5 (CMIP5) multimodel, changes in the space–time characteristics of the Pacific Decadal Oscillation (PDO) were analyzed. Empirical orthogonal function, regression, and power spectrum analyses were used to study the winter sea–air coupled system in the North Pacific region. Comparing the spatiotemporal characteristics of the PDO from the observed data for the periods 1850–1934 and 1934–2017, we found that, under the background of global warming, the intensity of the PDO is strengthened, and the frequency of the PDO mode is shifted to high frequency (the period is shorter). Then Taylor diagram analysis and power spectrum analysis were used to evaluate the simulation ability of 13 CMIP5 models of the PDO in the 20th century. On this basis, nine well-evaluated models were selected to compare and analyze the spatial and temporal characteristics of the PDO under different warming scenarios. The response of PDO to global warming in the model was consistent with the observed results.